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OleManRiver
(@olemanriver)
200+ posts Member

@mightymoe 😂. Run Forest run.   So surveying where you need to start by practicing catching a greased pig.  Once you can catch a pig then you can work on getting accepted to become a surveyor.  This whole earth rotating and wobbling and circling around the sun is one thing now we have to deal with plate tectonics and subsidence. I love it just meeps us on our toes and learning all the time. 

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Posted : August 4, 2022 9:29 am
SPMPLS
(@spmpls)
500+ posts Member
Posted by: @olemanriver

now we have to deal with plate tectonics and subsidence.

I have long referred to it as job security.

I may have shared this before, but these are the HTDP calculated velocities for several control points in the east SF Bay Area over a relatively small region. Our latest realization of NAD83(2011) is 2017.50, which was produced by the California Spatial Reference Center. Because of the delay in the rollout of the new NSRS, we are contemplating one more realization of NAD83 because 2017.50 has fallen apart in many areas in the western part of the state.

 

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Posted : August 4, 2022 11:21 am
OleManRiver
(@olemanriver)
200+ posts Member

@spmpls wow .  Y’all have your hands  full for sure. I don’t know if my simple brain could keep up with that much movement.  Job security for sure. 

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Posted : August 4, 2022 12:59 pm

RADAR
(@dougie)
5,000+ posts Member

@holy-cow 


GIF
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Posted : August 4, 2022 1:01 pm
holy cow
(@holy-cow)
10,000+ posts Member

Judge:  Mr. Expert Witness, explain this to me again.  Your survey plat from 1978 says the latitude and longitude of the point in question is X,Y.  Your survey plat from 1991 says the same exact pipe is at X1, Y1.  Your survey plat from 2022 says the rusty old pipe is now at X2,Y2.  Are you inept?

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Posted : August 4, 2022 1:18 pm
Dave Karoly
(@dave-karoly)
10,000+ posts Member

@holy-cow is the Judge using his set of 1970s statute books?

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Posted : August 4, 2022 1:40 pm
RADAR and OleManRiver liked

SPMPLS
(@spmpls)
500+ posts Member

"Hold on Judge, you are about to go for a wild ride in Geeksville." I think I could explain it in an understandable way. I have done it for upper level management and they have been fascinated, or appeared to be. Or maybe they just signed off on my resources requests just to make me go away and stop being the source of their headache?

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Posted : August 4, 2022 1:43 pm
holy cow
(@holy-cow)
10,000+ posts Member

@dave-karoly 

Quite possibly older than that.  Probably from a vague memory from some class 48 years ago led by a wizened old gent who studied the statutes in 19-aught-7.

Sort of what a lot of mentored land surveyors do today.

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Posted : August 4, 2022 1:47 pm
Rover83
(@rover83)
1,000+ posts Member
Posted by: @holy-cow

Judge:  Mr. Expert Witness, explain this to me again.  Your survey plat from 1978 says the latitude and longitude of the point in question is X,Y.  Your survey plat from 1991 says the same exact pipe is at X1, Y1.  Your survey plat from 2022 says the rusty old pipe is now at X2,Y2.  Are you inept?

No, Your Honor, I am not. Wegener proposed the theory of continental drift over a century ago. Even though it took some time to be accepted, it has been proven many times over. Science advances.

The tools that we use to establish positions upon the earth are continually being refined. So, too, is our understanding of the earth itself - and consequently the models upon which our coordinates are based.

That's a fact. The existence of changing geodetic coordinates neither invalidates the work of the past, nor that of the future. It simply is. We will continue to progress rather than remain stuck in the past, because we have a duty to do so.

As geospatial professionals, we have a multitude of tools at our fingertips to model where a point has been, where it is now, and where it is going. Supported by the able experts at such organizations like the National Geodetic Survey, we use these in our work, we document our methods, and we still honor bone fide rights laid down by common law, statutory law and case law.

As professionals we adapt. We adapt - as the medical profession did to the relatively recent acceptance (about the same time that continental drift was accepted) that the brain is plastic and not "hard-wired" as had been accepted for a long, long time. A great many individuals have benefited from professionals discovering and applying new methods over the course of our human history.

The mere fact that someone outside of a profession does not understand, or is suspicious of, advancement within that profession, and the changes that result from those advances, does not invalidate the work of the professionals who advance along with the profession.

 

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Posted : August 4, 2022 2:12 pm

holy cow
(@holy-cow)
10,000+ posts Member

Landowner to neighbor.  "Found the corner in no time at all.  My GPS said this was it."  "No, that big rock over there is just a big rock.  Heaven only knows how it got there."

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Posted : August 4, 2022 7:20 pm
Jitterboogie
(@jitterboogie)
1,000+ posts Supporter

@holy-cow 

....Glaciers. 😆 

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Posted : August 4, 2022 8:45 pm
MightyMoe
(@mightymoe)
5,000+ posts Supporter

Coordinates on plats didn't work well when they started showing up in the 1970's. To many assumed they could tie into the NAD27 monuments and survey to the property monument and be on it. Turns out that even the most accurate surveyors would miss it by small amounts but still not "on the cap" close. 

There are a number of large mine boundaries and DOT projects filed with coordinate basis from those days. However, if you "get on" the local control you would be good, instead of surveying from far off NGS points. 

Then came GPS,,,,,,,,,,,button pushers all thought those SPC coordinates were gospel. I remember following a large DOT project from the 80's that established control and monuments tied into the local NGS 27 monument control. Those were done using long traverses and adjustments with conventional equipment. Then we had to recreate the surveys using GPS and one of the newer surveyors who had never done big traverse runs was telling me how he missed the coordinates by 2'. I told him that I thought it was amazing that we were hitting the monuments that tight, he thought there was some big bust. 

It's was all perspective, someone that had run traverses for thousands of miles and someone who had only worked on little parcel jobs. 

The idea that a coordinate on a plat is so good it's fixed in stone is a new thing, us old timers know better. 

But,,,,,,if that coordinate can help square up parcel lines in the GIS I'm on board. 

There was a recent survey I completed. Along the south line of the parcel is a 1/4 corner. To the south of my survey is a parcel that was surveyed early on in the GPS surveying days (1995). On that survey was published a coordinate in state plane (meters) for the 1/4 corner which was a stone monument. Later DOT came along and remonumented the stone with a brass cap. Then I show up in 2022 and tie in the brass cap. Just for information I converted the 1995 state plane coordinate to Lat, Long. I missed it by .07', bear in mind that it's a 1995 coordinate for a stone and this is now a brass cap without any published coordinates. Frankly, I don't know how he got that close except for possibly a HARN point somewhere close by, but it's another example of how good GPS can be. 

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Topic starter Posted : August 5, 2022 5:46 am

OleManRiver
(@olemanriver)
200+ posts Member

@mightymoe I agree that coordinates on a plat alone are not the best approach.  Especially grid Northing and easting on something like NAD27 or NAD83  if those utilizing them do not understand how to properly handle them.  If it is allowed I will use a lat long for the gis and state datum and realization instead of State Plane coordinates and zone. But its not the coordinates that are at fault it is the measurements and person that derived them from whatever means. GPS solar observations traverse etc. along with the limits of its tools utilized. I found old monuments from nad27 at CLNC that had been set all over the base. I had great results on most of those monuments when I re measured in NAD83 and converted them transformation to nad83.  They all except a very few fell within the tolerances allowed when they were observed some many hears earlier. No difference in bearings and distances on any survey that has been done in chains and a transit that is retraced today. When we are compering measurements. Not evidence.  It happens in the public land system and metes and bounds. We are all humans we make mistakes our tools are not perfect. 

I was involved in the section and range break downs for row of e470 out west before I left private surveying to join the USMC. We used many different tools to do our work. Fast static gps, rtk, total station etc.  As we measured all the corners we found that some original monuments were so close to that present day tools and techniques it was amazing. I mean when you are hitting the same distance over terrain with gps and or long traverse you could only admire the work done gia chaining and transit. I mean not a nickles worth of difference. There was one corner that I could not leave undone i was just a i man / jr crew chief at the time and had just attended a class by Mouland or someone i can’t remember his name but his hot line was “no such thing as a corner not found “ any way i was doing a topo in an area solo with the 4800 rover and 4000ssi base. I finished up and the other crews were still busy doing work miles away. I took out the glo notes and re located a stone section corner where i was and leap frogged the base and rover as i walked following the glo notes. As i was following the notes and the calls to creek crossing and terrain and came close to the called platted distance I realized that section corner we found which was a newer monument disc etc someone set and i was determined that the original was still around. Now i was green and motivated.  I searched around looking for the stone. The monument disc was perfectly inline with east to west and north south fence. Barbed wire. I was just about to so well i did my diligence. But a tumbleweed literally changed my mind. I saw it going across the field as i stood on top of the hill. Stopping before it hit the north south fence line.  I walked a quarter mile and saw this pile of old tumble weeds and made a row about 50 feet or more off that north south fence line. I tied some flagging at couple hundred feet spacing in what i guessed was center and dug around and found evidence of old fence and post.  I went back to the disc monument and waited on the true chief to pick me up. He parked and grabbed his lunch bucket. I broke out the total station and wiggled in on the new line tumble weed line and saw i was missing the monument and spun a 90 to fence lines running east west of me. And was not withen what I thought was not close enough. So I wiggled and bucked in both ways took a few tries but as I got closer to the lines i was in a thicket of sorts. So grabbed my bush axe and as pretty as you please was a stone and we offset it and found the reference stone buried underneath as per glo notes  i was one excited green horn wanting to become a good surveyor  my boss said ji admire your desire and such but you just opened up a hornets nest  . I don’t know what all derived of that because a subdivision was tied to the disc and such but we did locate the stone and it fit the original notes but not the measurements .  

 

 

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Posted : August 5, 2022 8:32 am
Bill93
(@bill93)
5,000+ posts Member
Posted by: @mightymoe

Coordinates on plats didn't work well when they started showing up in the 1970's. To many assumed they could tie into the NAD27 monuments and survey to the property monument and be on it. Turns out that even the most accurate surveyors would miss it by small amounts but still not "on the cap" close. 

The McI\Entyre surveying text I used in 1982 was pushing that idea.

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Posted : August 5, 2022 10:50 am
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